Elastic fluid turbine



O. A. WIBERG ELASTIC FLUID TURBINE Original Filed July 8, 1 940 AWE/T )5Patented Jan. 5, 1943 Original application July "8, 1940, Se rial No.344,451. Divided and this application .February 18, 1942,:Serial No.431,403.

August 31, 1939 In Sweden Claims. (01. 253916.55

This invention relates to elastic fluid turbines and more, particularly.to steam or gas turbines of the, radial flow'type in .which two, or moreadditional sets of axial flow. blades are provided so as to be acted onby the driving fluid that has passed through the radial flow system, andin which said additional sets of axial flow blades are carried byaxially spaced annular turbine discs or disc sections, to the free outerends of which the blades are attached. The object of the invention is toprovide means for suppressing vibrations in said discs, especially inthe outer portions thereof.

A feature of the invention involves the provision of a rigid connectionbetween adjacent discs at their inner periphery so as to lock themagainst axial vibrations with relation to each other, and the provisionbetween the outer positions of the discs of an axial stay or staysrigidly secured to one of the respective discs and in frictionalengagement with the other disc.

In the accompanying drawing several embodiments of the invention areillustrated. Fig. 1 is an axial section of part of a radial flow turbineto which an embodiment of the invention has been applied. Fig, 2 is aplan view of the outer staying element of the embodiment shown inFig. 1. Figs. 3 and 4 are axial sections of modified forms of outerstaying elements.

With reference to Fig. 1 the numeral I indicates part of a radial flowblade system of a steam or gas turbine having, in addition to saidradial flow blade system, two annular sets of axial flow blades 2 and 3,respectively. The radial flow blades I are carried, in part, by an innerturbine disc section 4 and, in part, by an outer turbine disc section 5.The axial flow blades 2 are carried by the said disc section 5, and theaxial flow blades 3 are carried by a separate turbine disc I situatedaxially beside the turbine disc 5. The turbine disc section 5 isconnected at its inner periphery to the disc section 4 by a set ofradial bolts 8 and to the disc 1 by another set of radial bolts 9engaging holes in overlapping parts or flanges of the discs 5 and 1.Inside the discs 5-and 1 is shown a cylindrical member ID connecting alabyrinth plate II outside the turbine disc I to the turbine discsection 4, said member I0 being further connected by means of pins toanother labyrinth plate, not shown. It is considered that the parts ofthe turbine thus far shown are sufiicient as a basis for illustratingthis invention.

Provided between the outer portions of the discs 5 and I is an axialstay in the form of a cylindri cal lr'mg i 2 the axis, of. whichcoincides withthe turbine axis. One end of said ring isclamped totherespective turbine disc, as 5, and tothis..

end the ring is formedwith an nlarged=rounded end portion l3 engaging acorresponding .groove of the disc. Theotherend of. thering I2 .isiinfrictional engagement with its respective. turbine disc, ,as 1, andtothis 'end' the outersurface of the ring, bears againstthe inside ofanannular flange I4 projecting from the inner surface of disc I. The ringI2 does not extend fully to the said surface. The friction producedbetween the flange I4 and the ring I2 may act to suppress vibrations ofthe discs 5 and I to neglectable values.

In order to increase the friction between the free end of the stay ringI2 and the flange M, the ring may be provided with an additional mass I5at its free end, and slits may be cut in the ring from the free endthereof, as shown at I6 in Fig. 14, so as to form axial tongues I! eachcarrying a segmental additional mass. In rotation, said tongues I I willbe forced by the centrifugal force against the flange 3|] with a powerincreasing with increased speed of rotation and increased size of theadditional masses.

Instead of using an integral flange I4 a separate ring I B, Fig. 3, maybe used which is attached to the respective turbine disc, as I, by acaulking operation. In Fig. 3 is further shown a wear ring I9 let in agroove in the outer surface of the stay ring I2 at the free end thereofwhich bears against said separate ring I8,

In Fig. 4 is shown a flange 20 formed integrally with the turbine disc Iwhich presents a conical inner surface to be engaged by a correspondingconical outer surface of the stay ring I2 at the free end thereof. Alsoin this case the degree of suppressing the vibrations of the discsincreases with increased speed of rotation.

What I claim is:

1. An elastic fluid turbine of the radial flow type having incombination, a radial flow blade system, sets of axial flow blades,axially spaced annular discs to carry said sets of axial flow blades,connections between adjacent ones of said discs at the inner peripherythereof, one of said discs having on its surface facing the other discan annular flange concentrical with the turbine axis, and a stay ringloosely bearing against the inside of said flange by its oneend portionWhile being in engagement with an annular groove in the other disc by anenlarged portion at its other end.

2. An elastic fluid turbine of the radial flow type having incombination, a radial flow blade 4 system, sets of axial flow blades,axially spaced annular discs to carry said sets of axial flow blades,connections between adjacent ones of said discs at the inner peripherythereof, a separate ring attached to one of said discs by a caulkingoperation so as to form an annular flange concentric with the turbineaxis, a stay ring loosely bearing against the inside of said flange byits one end portion while being in engagement with an annular groove inthe other disc by an enlarged portion at its other end.

3. An elastic fluid turbine of the radial flow type having incombination, a radial flow blade system, sets of axial flow blades,axially spaced annular discs to carry said sets of axial flow blades,connections between adjacent ones of said discs at the inner peripherythereof, one of said discs having on its surface facing the other discan annular flange concentrical with the turbine axis, and a stay ringloosely bearing against the inside of said flange by its one end portionwhile being in engagement with an annular groove in the other disc by anenlarged portion at its other end, said stay ring having a wear ring letthereinto on the part of its outer periphery bearing against saidflange.

4. An elastic fluid turbine of the radial flow type having incombination, a radial flow blade system, sets of axial flow blades,axially spaced annular discs to carry said sets of axial flow blades,connections between adjacent ones of said discs at the inner peripherythereof, one of said discs having on its surface facing the other discan annular flange concentrical with the turbine axis, and a stay ringloosely bearing against the inside of said flange by its one end portionwhile being in engagement with an annular groove in the other disc by anenlarged portion at its, other end, said stay ring carrying at its freeend an additional mass in order to increase the friction against thesaid flange under the influence of the centrifugal force.

5. An elastic fluid turbine of the radial flow type having incombination, a radial flow blade system, sets of axial flow blades,axially spaced annular discs to carry said sets of axial flow blades,connections between adjacent ones of said discs at the inner peripherythereof, one of said discs having on its surface facing the other discan annular flange concentrical with the turbine axis, and a stay ringloosely bearing against the inside of said'flange by its one end portionwhile being in engagement with an annular groove in the other disc by anenlarged portion at its other end, said stay ring carrying an additionalmass at its free end and being cut by axial slits at said free end so asto form axial tongues each carrying a portion of said additional mass.

OSCAR ANTON WIBERG.

